Document 34Zm8dpaxXzQMmg6ev9G02MO

Monsanto industrial chemicals co. -r- ...... ........... R. E. Keller - TIB - St. Louis H. S. Bergen R. A. Lidyett - BESL - LLU J. P. Mieure -m R. H. Munch - TIB W. B. Papageorge - B2SK W. R. Richard - T3A D. Wood - B2SD Dick, In June this year a plan was developed with Bill Papageorge and others to learn more about chlorinated dibenzofurans in our Aroclor products. As a part of this plan it was decided that furans standards should be prepared and analytical methodology developed for the detection of at least 0.1 ppm for each furon homo leg. Laboratory mixtures of monochlorothrough hexachlorodibenzofurans have been prepared and characterization for homolog distribution is underway. Also, we have about one-man con tinuous effort on the method development work. As part of the plan it was decided that we should determine if Bayer has carried out "in-house" work of this type. The attached June 16 memo from Dave Wood to J. N. Haggart covers a request for this information. We have had no reply to this correspondence to our knowledge. Any infor mation or assistance you can provide on this point will be appreciated. During the past week a publication has appeared in the literature entitled "Identification of Chlorinated Dibenzofurans in American Polychlorinated Biphenyls" by R. W. Risebrough et al. of the University of California. A copy of this paper is attached. It shows the identification of chlori nated dibenzofurans in our Aroclor products except Aroclor 1016. We are now anxious to develop our own data for comparison with this publication. Regards, ss Attachments(2) R. E. Keller HONS 202304 D, Wood - St. Louis J. N. Jlaggart 504 0 H. S. Bergen - B2SL W. B. Papagcorge - B2 J. Mleure - T2P R. II. Hunch - T1D C. Paton - B2SC John, You will recall that Dutch researchers (Voss et al) found furano In chlorinated blphenyl3 produced by Prodelec and Bayer some four years ago. . Recently FDA has claimed to have detected these products In Aroclor and we will possibly see increased publication about these toxic contaminants develop. It would be appropriate to establish a technical dialogue with Bayer if they have carried out "in house" work in this area and Ralph Much will be writing to Dick Baxter about thlo. We need to develop our own methods to determine if indeed the chlorinated dibenzylfurans are present and what Is the potential hazard. I am asking Ralph to send copies to you when he contacts Dick in case there are any business implications in establishing such a technical contact of whlc /pep HONS 202305 dors (I) tion andcore *: U) data at nisly tion dry west tlow inny ' in nrd- the the OiliC ............. ... Um| <nr ^WB-nultIT--l"S.tn l>ancivco. I liese condition* would lend to increased tree growth during the following growing season (l ie 4). Antonin and winter climatic anomaly features. com bined with spring climate and the year-to-year autocorrela tion ol tree-ring widths, produce the Other ring-width anomaly features in t ip. 4 for the following growing season. Narrow ring width* south tit San Francisco, for example, imply heldw normal precipitation--an expected feature since winter precipitation in Utc Pacific North-west is negative lv correlated with winter precipitation in southern California*. The reconstructed values of athacore catch distribution data (Fig. 3) and inferred population distribution also seem to exhibit lung term changes over intervals uf ItltJyf or mure, which suggest (he possibility that lung term fluctua tions in the ocean-atmosphere system may lie insolvcd. I lie success of I he calibration of tree rings with ulhacore Caleb indicates Uic possibility of relating tree-ring varia tions to any type of biological variations which arc affected hy large scale elmiatic tlucltiuliuns. Such relationships may be qtunhlicil anti used In reconstruct objectively other elim.iitcally-caused biotic variations in the past. N. K. Ciank National Oceanic ami Atmospheric Administration. National Storme Fisheries i'rrrtcr, 5m/r/iu'c'jr Fi\hettcs Center, La Jolla. California ItflW T. }. UUOSlMO II. C. lutijrs l.vhorutory of Tree-Ring Research. Umvvnitv of Arizona. Tucson, Arizona M72I KvrM,s1 Drstrtrlur S. IVT4; mcriffd Mlf 4, IVU. r l -MjtiUf. v r , v, **+. la), iniimihvto * ....... as ^ . >/, Hi.sii. fft-* . ft X *hft ,rM .. *1. IN* 1 fwi. II M - r l4J ft. *w.wv..sv.sC \r,,s ,.s iotiii.,i >,1.1.,. i.nnkua * "'ll irlM Xt Wst,HS,*t t |#rsnvnt- I i *!As. fl tl Itutsmg J^7t iNI l i!hSitmal Mttmv I St*|tHC, Vmihw*r 4*tlurrvs l\ilr. Id- JsiH-l. * OntM trx. tt. tt . wbl C'lfct*. VI. 1. IVpf t s\h ntal (ittmr, / *\fc fluff., 1?l r rk>M. * VlK o. 1 , | ..ft I itstesmM I ITr/sH, 1. lit * f tt , *# Inrt rigufl.ai fl tww /H( i IpdiltloH Ptffhlht i* 4 drftlfNM tdW llflhtlthll) Hi I'llMfllttH Hvv'MWt IVKfcl. Oats may grots holler in h:iUt * depleted in oxygen 1H ami tlettloriuni Won.( growing oats ai different loupci-dure* m .ocr (,f dulcrcnt "0 and dcuicnum tl>) ahiiud.inccs, we uoliced ilui 0.11s giown in Antarctic water in "Inch is detdelctl in (> ,mj 15 by - 49 arid 4fX)",,, relalive 10 s1.1ml.11d mean occjii waicr (SMOW used as a comparative reference in hydiugen ..nd (lsytjen isoiope si udiesi. showed initial prowlh I -2 weeks mom r I ban did oais gum 11 in water coni.niung greater '*0 .uul I) conccnirntivuis. the oat* scented In grow belter ill w.uvr which was mosl dcpleicd 111 ilieslahtc istilopcs dirmiglioul die growth period. The mils were grown from ihe same batch of seeds in iwo seated glass-covered glass jars (approsmi.ncly to I) Tutni). live oat seeds were added to each jar, cuntammg die same amount rff vcrmiCidiic anil 500 ml water 10 winch 5 0 g R.iptdCird. a commercial fertiliser, hail been added One jar turn dined nietied glacial ice I'runi liic AiUareliC mill isotope conceuir.11 mn- of - 49'V,fi''0 (SMOW) and 4U0,,W) fi|> (SMOWl. llie miirr jar comaincd distilled oeeim water wulj . | U';^, 6"0 (SMOW) and 4 17',*, dl> (SMOW), Iklth jars were placed in llie chamber l Ihe same lime. 1 lie esperimem was repented three limes wuh new m.iicnals; once 1 lie grow 111 chandler as niaimamtd between (,7.tml 1 1 C, once between 24 and 2<>.h C`; and uucc the lemiier.iiiue PuCiuiilcd between 1.7 and 2h.<i *C, T.uch lime the 0.111 m the jar comaining water depleted in the heavy isotopes showed germmaiion 1-2 weeks earlier and seemed to grow belter throughout Ihe growth period, than oats grown in disnlkd ocean water. Using oats grown at sS C. ihe tirsi sign of germination in ihe jar containing water depleted in the heavy isotopes was 4 J after pluming. On the day b, eight plants (out of 2$) had ailained a licighi of 6 cm. The first sign of gcrmin.ii on in the j.ir wuh water containing the heavier isotope concentration, w.14 after 17 d. By the lime live plants had attained .1 height of (uni m ilm jar. in that with water depleted in the isotopes, 23 plains that had leached the tup nf the j,u (approximately 25 tin). Kasliulin' Observed that snow-water depleted tn I) increase* the yield of Cucumber*, radishes and spring wheat .omp.u.-J with controls grown m ordinary water id unspecrtietl woinpic cnniposttion. lie cites evpi'nmcnls on die egg priHluvluuy of hen* and the weight gain of suckling pigs. In boll) cases water depleted in L) was especially eHiticiu m tuomoimg puhIucov.i >. Although much ha* been done on the clt'cct of U enrivSn il wilier on biological Systems, we suggest dial lescaivh on 1 tic etfeei D-depleicd water on plant and animal growth may prove fruitful. A major source of waicr dcpleicd m |y hy over aid)".. 14t>*,,) coni pared with SMOW is snow and ice from the Antarctic polar plateau. Water depleted by 150-tMi"^, is readily available in the USA from Kocky Mountain snow precipilaimg above* llt.COO I'eciekialion. * Jiu D. Ciixsosi IhVINO f'clMlMlN US Croltn'it ol Sun'i'i . Ih'ttler, ( tilonulo 8U125 Micron) 1 iMuur Itt; i((ilit Juni 1. Ill), 1 kl'h.M. K . I*,l-1 ll'SMtl. SI. UlTKM.1l Itlfitlilicalioii of chloriiuitcd tliltoii/ofuritiis In Aiitcricun polychlortiiBtctl liiplteni Is MimiM.ns of embryos has soiiirihuud tn die r. i'uvI.i, r..c failures of several bird species, mciuttmg die sp.inonii.mks |l .fifiif'r III wo 1 uf SOU I Item Scotland1, llie whilol.rdid v, r 1 lo (//u fui'i-rii.t ullnt tllo) of Sctileswig Holstein1, and Urc hen mg MOHS 202306 . >Q*** ' A'eturr Vrit 256 2i,/, /y.'5 pills {Ltnr* trrcrtnaiui) of Lake Ortiario* SkUpccird c. ^ct include jl^-DDE (22*6n4^*cfilofPphenyH-U'dicWonu*ihy* terse), oilier chlorinated biocides anti/or ihetr flcriv.iirkcs. TlWr l CniOliliXlrd dt6citi--ri-.ifi i .-in cnrru.oflp ,n Arycior Clonheo and I'licnocior ;ind Ihe polychlorinated biphenyl* (PC'li'-*. -dl of which arc I'Cll 4-C 1 J-CI 6 Cl r.uj picscm u ennlaniinanls in Ihe eggs1'*. I'GIls are prcscm m high conceniraiions in ihc hird population* which suffer embryonic morlatily"*. Olfier organochtorme compounds which may he present in food bs include the chlorinated d-bed/odiosins and the chlorinated dibcnrofuriins (Fig, I). which are toxic to embryos in amounts* 1 less Ilian I ug They arc therefore among (lie nioM ifme substances known and arc Arc<(eir 1 S1K t I9I.1J1 Arncinf 12'4 Iivr-U) Arr>.kjf 1254 ! |4)ii) A(f\iOf 1200 t tWh Afoctor 1260 Out. AK3) ArotCo*1 1016 (IW72) Oo^K'n A-ftd rhenoctor Ul* U n ^ i mi 0 l fAt 0 2 i Mi 0.1 (IU) 0 2 ( 25) nh 1 4 02) 0.7 (5) 1 2 1601 0 2 1121 0 4 [2D 0 4 14I1J 0 .1 l.'Sl NO 5 0 f5G( KJ 0 f74f filial 1 4(X2i f U Ifti'j o ? ou 0-1 i 'Si Nl) 2 2 (2M 2 7 (21) Jo 11 !5 ,1 08 S4 13 6 possible causes of (he observed mortality. The chlorinated dibenrodioxiits and chlorinated dibctiynfurans, however, hase prosed cscccdingly ddlieull to detect in environmental samples in ihc concentrations at which ihey are cmkcicJ to he cnshryotoxic*'1*. The chlorinated dibenlodiosiusenter tlic environment as contaminants in preparations of the herbicide 2,4.5-T (refs 5 and it) and (he fungicide pentaeh^o^ophenlll,,,'. Chlorinated dibcnzofttrani liave been found in a f:rcnch {I'licnoclor l>l'(0 and a German (Clophen A60) PCH ami sverc shown to lie ihe active embryoioaie agent in Hiese picparaiions*. Tlsc technique* used, however, did ik'I detect chlotin.ncil dibcn/ofuratn in an American PCD, Aroclor 1260. Wc rcporl licrc die presence of chlorinated dibenzofurans in AtOCtor 1'CD, widely used in North America and Gtcat Britain, and in ilte same Atock'r 1260 preparation examined pieviously wdh negative findings*. Samples of PCI) examined include: Aroclor 1248, 1254, ant) 1260 (19691. Arnclor 1254 (i7ni; Aroclor 1016 (1972); and (lie same three preparations slutlicd by Vos rt atAroclor 1260, lot No. AK.-3; Clophen A*60, lol No. 912434; and Phcnocior OP-6, lot no! specified. The latter three PCD* were obtained front l>r Vos, the Olliers from the Monsahto Conipany in Hie scuts indicated to parentheses. PCDs extracted from cnviroiuucnta! samples most often have gas chromatographic prolilcs similar to those of PCD formula tions containing approximately 4g. 54 or 60*' chlorine. In ihc Aroclor kiics, the former two PCDs are equivalent to Aroclor 1248 and Aroclor >254. respectively. Aroclor 1260, Plu-noclor l>P6, and Oophcn AGO all coni a in approximately 60*; chlorine. Clilortnalcd dibenzofurans were identified in all Aroclor *rptcsseil ,n ut S'* PCD Values m patcnlhcsti rcpfeieiH quantity s pcrctmagr total tttoen/oluf at) NO. not detested ( <0001 pg g-') Amoumi of t'Ct) tanging Mom 10 to 2 0 t were d.-er-ivra m 400 ml he sane, plated on a Florin! column tilde, internal dumncT 5) 3 nun), and flitted with) an additional l.titxi nil hrone. ana luCLCSSise MXI nil solunrrs each uf }% dtcdiyl-ntiri.''c-are. Zi\ dtcthyl-cther-licvanc and acetone, at a rate of arpronm.iic'> ^ ml mm ' Themaiur portion of I he PCIt,is cluicdm lire lie uric fi action, wjmh wai discarded On addition of ll.r 5 *. inniurc Ht r u ics rir Ctillesled m si* Mivccrsisc 400 nil rotumes. To eliminate ihc pohir solvents, earl) chwie was evaporated iwiec iust u* di-ncss .inj users up each Mine in a minimal amouni id hesane. bath li.nmnr- n I mi besane, was Placed on a micrrvdiinuna ct'kimo1' and chnal wan 10 nil each of I *,, anti 20T* inclh) kite ttdornle in hetanr I Met? w cie also taken Iwtee uisl lev dryness and made 1o up a toluiwe tU I nd in hexane lo ehtmn.de the nieihjtcue chloride txToic g.n .........mo- graphic analysis Afuiuots of all fractions obtained bchne and a tier partitioning on nhimma were tnp-ch-d inln a ns ftKit class column containing t)Vl on Mx)-)20 mcsli hiipeltopsul m Tin-.or M l 22" and Itewleil-Packani 5700 gas ehioniaiographs cunipped "h **Ni eicsifim-cai'ltiie dcletlors PC Ms were found iu K rreheni m e.ich fraction elided from me Flonsd cnknnn m aininnus lo niierfere wall die dett'tiion of tiaee innijaiin.ints. P.iiiinonine on Hie ahiniina enlumns sepaiatctl nsosl of Ihc PC1I inicrfereih.c woo the I *. melhvlene ehionde fractions Un rcmosal id Iho mteifcicmc. dillertni peak patterns appeared in ihc ehiumalogiams m me M mclhylciK cldswide fraomos. Comliiiimds ciuimg in Ihe ;d*. nic'htk-ne chloride fiactmn were collected for mass srieeiitaneiii- anatiris using a 20:1 ctllncni stddler. ami a (rap consisting of a r.in li.srv mhe (I mm internat di-imctcr. tlkt mill king) bent io a f! shape uinne'sed m a liquid ndrogrn bath. Mediakne etdornk 12i". 4 ail m lu-.n-j was inpvled into ihc capillar) as a rmsc, lcnn, l -n>, a t ti nl nitcropipede. ami placed direct IV on (he mass tpcLlrniinier piobe The piohe was imrrtrsl inlo a GI'.C A| I MSW>2 high rcsiikriifii mars spcrlriimclcr and the ssdscnl icmtwcd hy the fpne pim p Hie ptppe was rapidly inseiiesl into the mil s.iwrec and multiple scam wetc corded in the on-line high resolution niosJc1*. preparations except Aroclor 1016, as well as in Clophen AGO and Phcnoclor 01*6. Aroclor 1016 is PCI) mixture containing approximately 42*; chlorine atssl has rridaccd Aroclor 1242 Fla, I Skeletal structures oft a, chlorinated biphenyl, r+v - 1-10; ), chlorinaied dibrn/ofurans, x+y TM e, chtormilcd dibenaodtoxim, r+; l-l. in many applications, principally as the diek-cirn. fluid m capacitors". Values reported in Table i represent ih< iuuI uf those composiMtls found in 400 ml Flortsil fractions 2-6 A lot at of 10-12 isomers was iilcnldml ill each PCD. Tun chtorin- 1 aled dibentofuran contaminants have been rcporlct! fur thc Clophen and I'ltenodcr previousiv*. our lint analyse-, of the Clophen revealed an additional live chlorinated dilH irofur.ins' 'r -I , I; The Structures contained fourtusischlurmc atoms Oilier dd-cnrofuftmt inslusling llwrse ehlrmnatcd lo a lesser cusnt nu> lute liccn present in Ihe liist aotl till fraction but this was noi c umim-d in detail as it contained substantial I'CD interference Keeeidl) synthesised 2,).2,li*icira-, 2.),4,7,8-pcnij- and 2T.4 6T.h- Imsacliliiroslilicii/iifufjii w-cre used to tiuanlify ten.i-. pent.i-. t K and hctilchltirodi|scn/i>furatis, resticciivcly. The farmer iw-i authentic siamlurds had fcicntmn times mi the OV 1 .rt....... Ihe same as those nf two dibcn/nfurans isolated fn<m ihc rt. It Vet* fl ti/.` dcivCICd no chlnrinnicd dilviiimfiir.ins in a a Aroclor I2f>0 picparaimn at a detection limn n' i pi'm Fractionation add examination of the identical Aiac'ar irm in our study eonlirnt llwir fimimgs h.isttl on the >i Hid ia'-'i bill resell the tnescncc nf H chlnrinaicd dil'eiirnini.nie id pi cit.tra non. having a total ennevnii-iln'd oi I's og g ' i'i (Table M. Ihe same workers also found dicihyt fttw r n.'i.ui of lire Oophcu AM! and Pliciinc'lsir l)l'6 lo Ik mu- li .................. in chick embryos than diethyl ether cstiacts o! Af-nfrr t.'fJ> Our study eonhrois those lindings on the basis nl eh Mi tr-jicd HOMS 202307 JOT * hlv* l'een ' 'sed in proporuon.it amounts. Their per- / xtwniic, effects, a . sigmlicance remain lo be Jeiermm.j "c thank j. Ai. tturkc. M. L. Toner and i. 0 Vos (or di-cussions; A. S. Kendc Tor siamj.irds of rt.inrimneii Jibcnrnfurjns; and F. C Walts for assisiance uh Hie mass siMCirmnciry, 1 Ins work ivas supported hy ihe C.in,i,j..n; Widhie Service. Naimoal Soon Foundation, ano NASA Gchald W Busses* Canatlion Wthihft Strnrr. Tvme ChfiniruU Zn nun, Ot.*n. Cut,v<l,i Khi OIIJ '^itAEL J. MuLvnur.L SfJWt ScIflicft Laboratory, Unbrernty of California. ft'ikr/ry, California 94720 flee so R. T. SimiNrrr A. L. UUHUNCAWt . BoAfa Marine Laboratory, Uhtocruty of California, Bo toga Hay, California 9492J R. W. Rise mooch . ., . Fig, l n, On chiofnatogiafli of a fraction of Arnclw 1154 containing nutlure of chlorinated biplicnrJs. tlihenrnfur.i ns, and napliltutrmtt hitntiiies ol pcakl aie gisc-n in die ic.sl. 6, Mai* ipcvirum of peak 2, a tetrathlorodibenrafurin. dibentofurun content: the identical Ctophen and Phenoctor contain II and 17 times niorc total chlorinated dibctuofurani, respectively, than the Aroclnf 126(1. A gui chrtmuuogrjrn tiioin| components derived from the Arnclnr 1254 obtained in 1966 is represented m Fi*. 2. The components were eluicd in the Second 4011 nil Horisil fraction ami recovered from I lie alumina column in 2l>?i methylene chloride-he sane. Each of the numbered peaks was trapped as described here, and idcnnlicil by mass speciromcinc analysis. A nominal mass plot or the high resolution mass spectrum of peak 2 it shown in Fig. 2. The plot includes all the tons with elemental compositions runging to the maximum empirical formula C,iillOi:CI,"CI."CI. The molecular ion cluster at nominal mir 304.310 fragments by successive losses of Cl to yield the ions at mle 269-271 and CO to the ions at mjr 241 -741. A minor loss of C from the peaks at mfr 269-275 hIsi) occurs to yield the ions al ml* 234-7Jg, followed by CO elimination to i/r 2D6-2I0, The group of peaks al mjr 112-114 are the doubly charged molecular ions. An identical spectrum was obtained from an uiiiltcntic standard of 2.3,7,lt-tcirachlnrodihenri.'liiran Thu latter compound hat ft reiemion lime identical lo that or peak 4. Peak 2 is. Ihntfart, pootlioful isomer. Tle accurale mass measurements for Ihft characterisik: ions tire within 2 p.p.m. PI Ikcakuiatciloaci masses. Peaks idtiHtficd on thischromatogram ami their relent inn limes relative to dieklrin are as follows: a nusitirc of iclra*and pcntachiprobipiirnyl (I 02): leiruclilorn- dilwurofuian (1.30); pcnluchlorobiptienyt (1.46); ictrachlorodi* hci'/ofuran 11.17); hcvtthlorpnaphiluilchc (I.7J); rwmChloroluphenyt (I.W>) . ` hesitchlofOilaphthiilene f2.00); and hcnljtldoronaphlhnlcnc (346). An alitpioi of cumbinetl fi.ictnms derived Imm ilic sunte Anwlor 12J4 way treated will) dl.l/nillilh.inc to assess Svtiettser any chlorinated orihu-hydrosytsn'iwnyls (t'rc-fiprausi were present. Gas cluiuiiaiograplnc analysis of the saiitpb- tvlire and after ircainsvof resulird m idem is .it vhiniiiuipgi.iipv As large ipiamiues of 1'Clli have entered the glnb.il environnieiu<>'-', it may k- assumed that the contaminant tlibciirofurans 1*^**4 CtkeNry J); Mi* m '' 'IVWMdiWrgg*' Wtlff Krw^WCWm HudiJ, HexySWI M 1414 **h Sms.#* CA4vri >||*. * n***A, J . i , Ilf, 1 1TJ JttfWTJj. R- .. lad ii|H m M r. 1. J., Mr*. i,* 1 M . tPid M*t*. R . r-t* iu , Ml ?-!* Jlt4* * I^MftoltisiUdni, ii M . wi it* . Vulnef. ]Ml l^f 1 khO'. wet ri ti L ., Oan. S . L.. ,,J Ha--f y. W Save ( ai-w>. r.,ir.. *. ftS-tll * V`W J CJ . Cntisw J It S'* 4r Maaa II L. <<n N,4> a, Sitvw. * C til. Vst* R if. fst,f < HIM.I Ihcit . t *2v 4J J < ||7ll( ^'*i4^ t (i . t ftmtm //M , I. fWjl ' I li4Maf4 w R .WS'WrMtttt,hn *K r. 4 1 Jf l rM. a. i, m n*7ji fW Rm.- * K prtsl fcJcnK4*n, M flWM /*r*l# . J. iT-tl llin^. Md4|h<nri, H sn4 M . 44. 4 Inft . J}V. 4J. 104 II N)fl IM } f ] 1 (I, stkHist 'Hh. 4 ft*Ua It MAs C 4ti isyf 7 Cdmmil at AlWf M Scirilc d'*J J.h|he4<tvr> ^lag*4. I**In 1 fttnrn. \ , ansi Hfiilhri|t I dinhui, I, |* fti nf^i. MMs is <1^# . a**Ih4*V*i > r H I . Hft^iWL R, R.. t*4 n. JN M ML., d* MrHh*. J. 4.4 4m fl# fArW.. 14, l4a.M!s fff Tfk A J, . OU*n> R. W. MiR. V , Jjr ,Wif 4 lUil JU^flf'dl * I f 1 . dotj A. I*,, t'jnnm* Wl* Pn\ft. I. It - * 1147 j * * Rm 1. C> W . ji|J foakrl, l' | , / l't4 ft*%, Rsi t *** (<n <h# of<s%> "J(r4CRNM. >V. , Joharlt. A U . OHvo*, M . MM t* . AV*r. 174. JV MS I. tl.. M. c. Ml 4 V9, R II., Sm<m u> Ri^*iiv*h, H. N4` KkIm. r., pfk*l Ol Rw llvnitn, 1 ti.. tn# Nhh r*. N , A.Mtrtr J2t. iu.|7I>7<IM*l IVitftc breadth in Hryocoa as i lest of compelilwo theory 1 | Ctssrcririun theory predicts thftt inlraspeciflc *nsl iprrrspnHie competition should often have opposite etlccts on iW me of resources by a population, the former nitrcasmg. rtic latter deerrastng, she range of resource aciua.lv Field data supiniriiftf these predictions ire will tun for the interspecific cat'-' Nu ire ivitrcc for the at-i-Hpecilte condition, and wy Imw been unalsi* to hn.t %t nrcroscc demonstrating hutH citeds within a single srfvits We ihcrefore report here the verification of him prc-tjkiioni in respect nf cnHiklemn fer spjee t>> He OHpftytic tsrjoroan Alcroiu4ntm htruimm: less extentn c data suggesting Hie same dlRb aha other h()Oitum air oho :ported Idnspecilic competition ihnPd resalt in on increase in the xmgc oT a resource spec tram <ned by a spenn. as .it high |W i pul at ion levels the .ahaataps to any imtisKJual '<i tviii-j at the cnmnitltionhr-c Ofdmiuni of a rrst-.f.r (T-..tacni are otlscl hy ilts- inrewic mxrwsi'ccilie umi|srun.m hsiii* tlu-re (Fig. lul; this is she 'pvMWlp^t t>f euti.il upp-' tia.ii i ,tf M.icArihtir1 Iiiicrspecitic uniiiitlmon, mi Hk i ilie rliand, shimld tend to restrict She range of ths- ronmrr -illrjSiiu used hy a species, as iftdividiiais aiis'iuptltig in i iplijt marginal resources cannot do lu as crtictcnlty ns HONS 202308